# Retiring LevelDBs with the new FST attr backend

- Institution: CERN
- Department: HEP Computing
- Speaker: Abhishek Lekshmanan
- Year: 2023
- Language: English
- Subjects: Computer science
- Source: [CERN](https://videos.cern.ch/record/3003014)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

Until EOS version 5.1.8, FST metadata on FSTs were stored in a leveldb, which was often heavily contended during writes. We added a feature to move the metadata to attributes. With a minimal configuration, we should be able to switch to the new backend and FSTs automatically move from one backend to another at startup. Additionally there is some tooling to inspect all this. We briefly explain all of this so that sites can get ready to use the new backend..

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## Lectures

1. [Retiring LevelDBs with the new FST attr backend](https://invisiblenetwork.ai/learn/cern/3003014/4d86fa6aed38), 11 min (CERN's player)